Worldwide, service providers have started offering audio-visual services to users of mobile and stationary data processing equipment via broadcast, multicast or unicast networks. The services use communication technologies based on, e.g., aerial connections, cable connections, or connections using satellite dishes. Examples of such communication technologies are DVB-H (Digital Video Broadcasting—Handheld, a mobile TV format), DVB-T (Digital Video Broadcasting—Terrestrial), T-DMB (terrestrial Digital Multimedia Broadcasting), S-DMB (satellite Digital Multimedia Broadcasting), ISDB-T (Integrated Services Digital Broadcasting—Terrestrial), DAB-IP (Digital Audio Broadcasting used for the transmission of IP (Internet Protocol data packets via DAB digital radio), MBMS (Multimedia Broadcast Multicast Service, offered via GSM or UMTS cellular networks) etc. Examples of such services are generally referred to as “Mobile TV” or “Digital TV”, wherein audiovisual content information and other electronic files are distributed via point-to-multipoint networks to end-user devices.
In order to inform the end-user about the content information available from these services, a description of the content information is typically made available via a so called “Electronic Service Guide” (ESG), or an Electronic Program Guide (EPG). The expression “Electronic Program Guide” is often used to refer to an overview of services available to the end-user. Such an ESG functions as the entry-point for the end-user to all such services that are available. In order to receive a service at a mobile device, an end-user device retrieves an ESG. The ESG comprises service information data containing, e.g., a program guide (metadata including e.g. title, description, genre, time), subscription and billing information (price, URL to acquire the proper credentials and entitlements required to consume the content provided by the service), access method information (Service Discovery Protocols or: SDP's, IP addresses, MPEG2-TS PIDs etc), interactivity information (for, e.g., voting or gambling) and auxiliary data. The service information data, often configured in tables, provides information about the content service (audio, video and/or files). The content information can then be received through user interaction with the ESG.
Typically, Mobile TV broadcast networks and Digital TV broadcast networks are bandwidth-constrained and the number of allocated live broadcast channels is limited. Therefore, methods exist to distribute content during off-peak hours, such as night time, and to present these channels during prime time. Such methods virtually increase the amount of channels available to the end-user.
For example, the OMA BCAST standard defines both a distribution window and a presentation window for a broadcast program. The content can be received via the broadcast channel during such distribution windows for being stored locally at the receiver, but is scheduled to be presented to the end-user during the presentation window. In another example, such content could also be distributed via memory cards that are to be inserted into the end-user device. In yet another example, this content could also be downloaded from the Internet, and stored at the end-user device.
For the content provider, it is important to guarantee that such content is being played out only in a particular time window and that the content can only be consumed by the end-user under pre-determined conditions, e.g., as specified in the licensing agreement with the broadcaster, the agreement made with the advertiser, and/or the agreement with the end-user having subscribed to the service. The scheduled play out time is important, for example, because the advertiser is targeting a certain audience that is expected to watch the broadcast at the play-out time as scheduled.